Measurement of particle compressibility can provide information about the mechanical properties and the structure of the particles that can be useful in many applications, including research and development and quality assurance for particle manufacturing and subsequent processing.
One application of compressibility measurement is the monitoring of modifications to particles as they are engineered for specific applications. In particular, the compressibility of small particles can change due to the addition of “cargo” or “payloads” to the particles. The incorporation of, for example, molecules, e.g., biomolecules, into the interior of micelles or emulsions or into the normally empty volumes of dendrimers will reduce the compressibility of these particles. Measurement of compressibility and changes in compressibility of the particles can be used to monitor the uptake of these molecules, providing a quality control process for the functionalization of small particles. In medicine, these measurements can monitor the uptake of diagnostic or therapeutic agents, e.g., into nanoparticles for delivery to cells either during particle manufacture or at the point of functionalization. This could include final steps that take place in the clinic immediately prior to the introduction of loaded particles to a patient. Release of cargo from particles can also be monitored.